Issue 7, 2015

Mixing-sequence-dependent nucleic acid complexation and gene transfer efficiency by polyethylenimine

Abstract

Polyplexes, complexed nucleic acids by cationic polymers, are the most common forms of nonviral gene delivery vectors. In contrast to a great deal of efforts in synthesizing novel cationic polymers and exploring their extracellular and intracellular delivery pathways, polyplex preparation methods of mixing nucleic acids and cationic polymers are often overlooked. In this study, the mixing sequence, that is adding nucleic acids to polymers or vice versa, was found to greatly affect complexation of both plasmid DNA and siRNA, polyplexes’ size, and polyplexes’ surface charge, which all collaboratively affected the transfection efficiency and cytotoxicity. Adding polyethylenimine (PEI), the most conventionally used standard in nonviral gene delivery, to plasmid DNA and siRNA resulted in larger polyplexes, higher gene expression and silencing, but higher cytotoxicity than polyplexes prepared in the reverse order. Based on the experimental results, the authors developed a model that gradual addition of cationic polymers (e.g., PEI) to nucleic acids (e.g., plasmid DNA and siRNA) incorporates more copies of nucleic acids in larger polyplexes in a smaller number, results in higher gene expression and silencing levels in transfected cells, and generates higher cytotoxicity by leaving more free polymers upon complete mixing than the other mixing sequence. The proposed model can be explored using a broad range of cationic polymers and nucleic acids, and provide insightful information about how to prepare polyplexed nonviral vectors for efficient and safe gene delivery.

Graphical abstract: Mixing-sequence-dependent nucleic acid complexation and gene transfer efficiency by polyethylenimine

Article information

Article type
Paper
Submitted
06 fev 2015
Accepted
06 mar 2015
First published
18 mar 2015

Biomater. Sci., 2015,3, 1124-1133

Author version available

Mixing-sequence-dependent nucleic acid complexation and gene transfer efficiency by polyethylenimine

S. K. Cho, C. Dang, X. Wang, R. Ragan and Y. J. Kwon, Biomater. Sci., 2015, 3, 1124 DOI: 10.1039/C5BM00041F

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements